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Erratum: Importance of Emulsification in Calibrating Infrared Spectroscopes for Analyzing Water Contamination in Used or In-Service Engine Oil. Lubricants 2018, 6, 35
Open AccessArticle

Influence of Sample Mixing Techniques on Engine Oil Contamination Analysis by Infrared Spectroscopy

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Department of Physics, Southern Illinois University Carbondale, 1245 Lincoln Dr. Neckers 483-A, Carbondale, IL 62901, USA
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Plant, Soil and Agricultural Systems, Southern Illinois University Carbondale, 1205 Lincoln Dr., Carbondale, IL 62901, USA
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Department of Agricultural Machines and Equipment, College of Agricultural Engineering Sciences, University of Baghdad, Baghdad 10071, Iraq
*
Author to whom correspondence should be addressed.
Lubricants 2019, 7(1), 4; https://doi.org/10.3390/lubricants7010004
Received: 17 November 2018 / Revised: 8 December 2018 / Accepted: 3 January 2019 / Published: 8 January 2019
For the most reliable and reproducible results for calibration or general testing purposes of two immiscible liquids, such as water in engine oil, good emulsification is vital. This study explores the impact of emulsion quality on the Fourier transform infrared (FT-IR) spectroscopy calibration standards for measuring water contamination in used or in-service engine oil, in an attempt to strengthen the specific guidelines of ASTM International standards for sample preparation. By using different emulsification techniques and readily available laboratory equipment, this work is an attempt to establish the ideal sample preparation technique for reliability, repeatability, and reproducibility for FT-IR analysis while still considering the ease and efficiency of the technique. This study demonstrates that a stable emulsion within a sample, which depends heavily upon the method, provides a reliably consistent homogenous sample for quantification purposes with FT-IR analysis. Analysis of variance (ANOVA) modeling and limit of detection calculations demonstrate the stability of the emulsion. The results reveal that setting a mixing time for a calibration standard depends on the emulsification process. Inserting a probe directly into a sample (direct sonication) allows for a rapid, stable emulsion with high reproducibility. Indirect sonication produces relatively non-miscible liquids of different densities. The pan-shaker produces a reasonably stable emulsion, but without the long-term stability or quick production time of direct sonication. Reaction time plays a critical role in the rotary mixing method, which leads to a slow development of emulsification. View Full-Text
Keywords: infrared spectroscopy; mixing methods; emulsion; water contamination; lubricating oils infrared spectroscopy; mixing methods; emulsion; water contamination; lubricating oils
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MDPI and ACS Style

Holland, T.; Abdul-Munaim, A.M.; Watson, D.G.; Sivakumar, P. Influence of Sample Mixing Techniques on Engine Oil Contamination Analysis by Infrared Spectroscopy. Lubricants 2019, 7, 4.

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